Randall is correct, as far as I know.
It's a Duncan-Miller Automaton parking meter from the early to mid 1950s. Production didn't last very long because kids were sticking razor blades in the coin slot. The next person to put a coin in, and push the "button," got their finger sliced up pretty bad.
I'm interested in buying any of these meters. I'm trying to write a service manual on these meters. Please contact me via PM.